L-Carnitine

How it works

It carries fatty acids into the mitochondria — the part of the cell that turns fat into energy.

What it’s used for

• Carnitine deficiency, e.g. in dialysis patients (approved)
• Fat loss and exercise performance (not proven)

What the research shows

• Works well for real carnitine deficiency.
• Little evidence it helps healthy people lose fat.

Side effects & risks

• Nausea and stomach upset
• A fishy body smell
• Injections need a sterile product

Is it legal?

Injectable levocarnitine is a prescription medicine for carnitine deficiency (e.g. in dialysis patients) in the US and several European countries. Use for fat loss or performance is not an approved indication.

Storage & safe handling

• Mix with bacteriostatic water: let it run slowly down the inside of the vial and swirl gently — never shake.
• Store the mixed vial in the fridge and follow the use-by period on the label.
• Wipe the vial top with alcohol and use a new sterile needle and syringe every time.
• Rotate injection sites so the same spot is not used again and again.
• Put used needles in a sharps container, not the household bin.
• Get medical help for redness that spreads, fever, swelling or trouble breathing.